Sensitive Electrochemical Detection of 4-Nitrophenol with PEDOT:PSS Modified Pt NPs-Embedded PPy-CB@ZnO Nanocomposites

Abstract

In this study, a selective 4-nitrophenol (4-NP) sensor was developed onto a glassy carbon electrode (GCE) as an electron-sensing substrate, which decorated with sol–gel, prepared Pt nanoparticles- (NPs) embedded polypyrole-carbon black (PPy-CB)/ZnO nanocomposites (NCs) using differential pulse voltammetry. Characterizations of the NCs were performed using Field Emission Scanning Electron Microscopy (FESEM), Energy-Dispersive Spectroscopy (EDS), X-ray Photoelectron Spectroscopy (XPS), Ultraviolet–visible Spectroscopy (UV–vis), Fourier Transform Infrared Spectroscopy (FTIR), High Resolution Transmission Electron Microscopy (HRTEM), and X-ray Diffraction Analysis (XRD). The GCE modified by conducting coating binders [poly(3,4-ethylenedioxythiophene) polystyrene sulfonate; PEDOT:PSS] based on Pt NPs/PPy-CB/ZnO NCs functioned as the working electrode and showed selectivity toward 4-NP in a phosphate buffer medium at pH 7.0. Our analysis of 4-NP showed the linearity from 1.5 to 40.5 µM, which was identified as the linear detection range (LDR). A current versus concentration plot was formed and showed a regression co-efficient R2 of 0.9917, which can be expressed by ip(µA) = 0.2493C(µM) + 15.694. The 4-NP sensor sensitivity was calculated using the slope of the LDR, considering the surface area of the GCE (0.0316 cm2). The sensitivity was calculated as 7.8892 µAµM−1cm−2. The LOD (limit of detection) of the 4-NP was calculated as 1.25 ± 0.06 µM, which was calculated from 3xSD/σ (SD: Standard deviation of blank response; σ: Slope of the calibration curve). Limit of quantification (LOQ) is also calculated as 3.79 µM from LOQ = 10xLOD/3.3. Sensor parameters such as reproducibility, response time, and analyzing stability were outstanding. Therefore, this novel approach can be broadly used to safely fabricate selective 4-NP sensors based on nanoparticle-decorated nanocomposite materials in environmental measurement.

Nanocomposites with ZrO2@S-Doped g-C3N4 as an Enhanced Binder-Free Sensor: Synthesis and Characterization

“…A previous study also reported similar observations. 2 The electrochemical area of the bare electrode was 0.0241cm 2 , whereas the active surface area of the modified electrode was calculated from the slope of the peak current versus V 1/2 plot and was found to be 0.1327 cm 2 . On the other hand, the sensitivity of the modified electrode was calculated to be 4.9 μA mM –1 cm –2 .…”

“…Finally, the modified binder-free electrodes were used for electrochemical measurements. 4-NP, a known environmental pollutant, , was used to demonstrate the sensing ability of the modified electrode.…”

“…Researchers are developing several new instrumental techniques and strategies to maintain a secure environment; however, efficiency and costs are often not yet optimized. Recently, different methods have been developed to detect 4-NP by the use of semiconductor nano-composites. − In this aspect, nitro-phenols have the potential to cause significant harm to humans, plants, microbes, and plankton. Nowadays, due to their expanding use in the production of drugs, fungicides, herbicides, insecticides, and dyes, nitro-phenols have become focus areas of research. − …”

Electroless Deposition of Gold on a Glassy Carbon Electrode (GCE) Surface for Selective Detection of Hydrogen Peroxide

“…Metal nanoparticles are essential in modern analytical chemistry as nanoparticles can be used to make sensors that provide better responses from organic and inorganic substances than ordinary metal surfaces. [18][19][20][21] Gold nanoparticles, in specifically, have proven to be ideal for creating customized electrodes. [22][23][24] As a result, many organic and inorganic molecules are physically chemisorbed on gold nanoparticles without losing their catalytic properties.…”

“…Metal nanoparticles are essential in modern analytical chemistry as nanoparticles can be used to make sensors that provide better responses from organic and inorganic substances than ordinary metal surfaces [18–21] . Gold nanoparticles, in specifically, have proven to be ideal for creating customized electrodes [22–24] .…”